• The Transactions of the Korean Institute of Power Electronics
• /
• v.26 no.6
• /
• pp.397-403
• /
• 2021

In this paper, phase shedding algorithm that measuring to converter's input and output parameter during real-time to control the number of driving converters is proposed. The proposed phase-shedding algorithm drives the DVR power supply with the optimal converter's combination without the loss calculation curve and the lookup table in which the efficiency is measured in advance. The proposed algorithm was implemented through a digital controller and verified in a two-modular LLC converter with a single rated power of 60 Win a 120 W DVR power supply system. Experimental results are presented to prove the validity of the proposed algorithm.

• ETRI Journal
• /
• v.45 no.4
• /
• pp.713-723
• /
• 2023

Game bots are illegal programs that facilitate account growth and goods acquisition through continuous and automatic play. Early detection is required to minimize the damage caused by evolving game bots. In this study, we propose a game bot detection method based on action time intervals (ATIs). We observe the actions of the bots in a game and identify the most frequently occurring actions. We extract the frequency, ATI average, and ATI standard deviation for each identified action, which is to used as machine learning features. Furthermore, we measure the performance using actual logs of the Aion game to verify the validity of the proposed method. The accuracy and precision of the proposed method are 97% and 100%, respectively. Results show that the game bots can be detected early because the proposed method performs well using only data from a single day, which shows similar performance with those proposed in a previous study using the same dataset. The detection performance of the model is maintained even after 2 months of training without any revision process.

• Journal of Communications and Networks
• /
• v.18 no.5
• /
• pp.837-845
• /
• 2016

Providing a customer with tailored location-based services (LBSs) is a fundamental problem. For location-estimation techniques with radio-based measurements, LBS applications are widely available for mobile devices (MDs), such as smartphones, enabling users to run multi-task applications. LBS information not only enables obtaining the current location of an MD but also provides real-time push-pull communication service. For indoor environments, localization technologies based on radio frequency (RF) pattern-matching approaches are accurate and commonly used. However, to survey radio information for pattern-matching approaches, a considerable amount of time and work is spent in indoor environments. Consequently, in order to reduce the system-deployment cost and computing complexity, this article proposes an indoor positioning approach, which involves using Asus Xtion to facilitate capturing RF signals during an offline site survey. The depth information obtained using Asus Xtion is utilized to estimate the locations and predict the received signal strength (RF information) at uncertain locations. The proposed approach effectively reduces not only the time and work costs but also the computing complexity involved in determining the orientation and RF during the online positioning phase by estimating the user's location by using a smartphone. The experimental results demonstrated that more than 78% of time was saved, and the number of samples acquired using the proposed method during the offline phase was twice as much as that acquired using the conventional method. For the online phase, the location estimates have error distances of less than 2.67 m. Therefore, the proposed approach is beneficial for use in various LBS applications.

• Journal of KIISE
• /
• v.43 no.9
• /
• pp.983-997
• /
• 2016

Many available online product reviews for any given product makes it difficult for a consumer to locate the helpful reviews. The purpose of this study was to investigate automatic helpfulness evaluation of online product reviews according to review information types based on the target of information. The underlying assumption was that consumers find reviews containing specific information related to the product itself or the reliability of reviewers more helpful than peripheral information, such as shipping or customer service. Therefore, each sentence was categorized by given information types, which reduced the semantic space of review sentences. Subsequently, we extracted specific information from sentences by using a topic-based representation of the sentences and a clustering algorithm. Review ranking experiments indicated more effective results than other comparable approaches.

• Proceedings of the Korea Contents Association Conference
• /
• 2008.05a
• /
• pp.732-737
• /
• 2008

As e-learning is recognized in new education form, Learning Management System that manage general activity of learning to maximize effect of education is being developed actively. Usually, Learning Management System includes course registration and learning as well as learner's learning recording and tracking, evaluation in online. But, most systems is lacking a tool that learners can collaborate with companion learners, and planning learning and set valuation basis as leading. In this paper, we can expect effective collaborative learning activities because can make debate and team project smooth by suggesting collaborative learning module that can drive voluntary participation such as group formation, learning plan, mutually estimation as leading to learner in Learning Management System of blended learning base that support online and offline environment both.

• The Journal of Korean Society for School & Community Health Education
• /
• v.22 no.2
• /
• pp.75-91
• /
• 2021

Purpose: The purpose of this article is to clearly describe research trends on health life expectancy using oral health indicators that have been published from 2010 to 2020 then suggest the direction of future research. Methods: Online academic databases in English (PubMed, Web of Science and Embase) were used to find those articles by applying a variety of keywords, including terms (adjusted life year, adjusted life expectancy, dental and oral). We identified relevant articles based on the following classification method of Mathers: (1) health gaps, (2) health expectancies. Results: Among 1,728 articles from the online databases, the final 13 studies satisfied the inclusion criteria and were selected for analysis. Health life expectancy studies indicate that research growth was recently achieved overseas. Among the literature collected in this study, 10 studies using health gap indicators yielded seven Disability-Adjusted Life Year (DALY), and three calculated Quality-Adjusted Life Year (QALY), which differed in the nature of the survey data used in the study measuring DALY and QALY. There are only three health expectancies and the number of papers were smaller than the health gap study. Conclusion: Establishing a foundation to calculate health life expectancy indicators through the development and improvement of oral health level are needed. More studies in the area of health life expectancy estimation research is based on actual prevalence and oral health-related quality of life are also needed.

• Journal of the Korean Society of Food Culture
• /
• v.37 no.6
• /
• pp.495-502
• /
• 2022

This study aimed to investigate the need for dietary education and programs for young Koreans belonging to single-person households in the metropolitan area. A total of 500 young adults aged 19-34 participated in the study through an online survey. Participants responded to questions on general characteristics, dietary problems, and the need for dietary education and programs. The subjects were divided into three groups as follows: Undergraduate students, employed workers, and others. Among the subjects from single-person households, 20.2, 67, and 12.8% were undergraduate students, employed workers, and others, respectively. When asked for their estimation of an appropriate self-pay when participating in a cooking class, 39.8% of total subjects responded '5,000-10,000 won'. The most preferred program for young adults in single-person households was the 'support food package'. For the preferred method of dietary education, undergraduate students showed a greater preference for classes 'at campuses'. However, employed workers and others had a higher preference for 'non-face-to-face online classes'. Undergraduate students tended to generally have a higher preference for dietary education and support programs compared to employed workers and others. This study provides data that will be useful for establishing healthy dietary policies and education programs for young single-person households in Korea.

• The Journal of Korean Medicine
• /
• v.44 no.3
• /
• pp.74-86
• /
• 2023

Objectives: The purpose of this study was to examine search trends and their meanings for major uninsuired Korean medicine (KM) treatments through analysis of an online portal search results. Methods: Keywords searches were performed using Naver Datalab on 4 July 2023. From January 2016 to June 2023, monthly relative search volume (RSV) for keywords 'pharmacopuncture', 'Chuna', and 'needle-embedding therapy', and 'herbal decoction' were extracted with a score between 0 and 100. For the obtained RSVs, longitudinal changes over time, characteristics according to sex and age group, and correlations between them were investigated. Results: The ranking of RSV for each keyword has changed from 'Chuna', 'herbal decoction', 'needle-embedding therapy', and 'pharmacopuncture' to 'Chuna', 'herbal decoction', 'pharmacopuncture', and 'needle-embedding therapy' after 2019. Overall, the RSV of needle-embedding therapy continuously decreased, while that of pharmacopuncture continuously increased. In 2019, a rapid increase in the RSV of Chuna was observed, and in 2020, a rapid increase in the RSV of herbal decoction was observed. There was a difference in the longitudinal change pattern of RSV for the keywords by age group. Importantly, in the elderly, changes in RSV were observed in a favorable pattern to KM treatment. Conclusion: Our findings enable estimation of the public's interest and its changes for the four uninsuired KM treatment, and can be used as basic data to strengthen health insurance coverage in Korea. Specifically, changes in interest in KM treatments according to sex and age can be referred to.

• International Journal of Computer Science & Network Security
• /
• v.24 no.2
• /
• pp.101-112
• /
• 2024

Telugu language is considered as fourth most used language in India especially in the regions of Andhra Pradesh, Telangana, Karnataka etc. In international recognized countries also, Telugu is widely growing spoken language. This language comprises of different dependent and independent vowels, consonants and digits. In this aspect, the enhancement of Telugu Handwritten Character Recognition (HCR) has not been propagated. HCR is a neural network technique of converting a documented image to edited text one which can be used for many other applications. This reduces time and effort without starting over from the beginning every time. In this work, a Unicode based Handwritten Character Recognition(U-HCR) is developed for translating the handwritten Telugu characters into English language. With the use of Centre of Gravity (CG) in our model we can easily divide a compound character into individual character with the help of Unicode values. For training this model, we have used both online and offline Telugu character datasets. To extract the features in the scanned image we used convolutional neural network along with Machine Learning classifiers like Random Forest and Support Vector Machine. Stochastic Gradient Descent (SGD), Root Mean Square Propagation (RMS-P) and Adaptative Moment Estimation (ADAM)optimizers are used in this work to enhance the performance of U-HCR and to reduce the loss function value. This loss value reduction can be possible with optimizers by using CNN. In both online and offline datasets, proposed model showed promising results by maintaining the accuracies with 90.28% for SGD, 96.97% for RMS-P and 93.57% for ADAM respectively.

• Steel and Composite Structures
• /
• v.53 no.1
• /
• pp.103-114
• /
• 2024

This study proposes a new hybrid approach that utilizes post-earthquake survey data and numerical analysis results from an evolving finite element routing model to capture vulnerability processes. In order to achieve cost-effective evaluation and optimization, this study introduced an online data evolution data platform. The proposed method consists of four stages: 1) development of diagnostic sensitivity curve; 2) determination of probability distribution parameters of throughput threshold through optimization; 3) update of distribution parameters using smart evolution method; 4) derivation of updated diffusion parameters. Produce a blending curve. The analytical curves were initially obtained based on a finite element model used to represent a similar RC building with an estimated (previous) capacity height in the damaged area. The previous data are updated based on the estimated empirical failure probabilities from the post-earthquake survey data, and the mixed sensitivity curve is constructed using the update (subsequent) that best describes the empirical failure probabilities. The results show that the earthquake rupture estimate is close to the empirical rupture probability and corresponds very accurately to the real engineering online practical analysis. The objectives of this paper are to obtain adequate, safe and affordable housing and basic services, promote inclusive and sustainable urbanization and participation, implement sustainable and disaster-resilient buildings, sustainable human settlement planning and management. Therefore, with the continuous development of artificial intelligence and management strategy, this goal is expected to be achieved in the near future.